On-demand (OD) computing is one of the enterprise models which has gained immense popularity. And, in it basically the computing resources are made accessible to the end-user as and when required. The resources may be maintained within the end-user’s enterprise, or are made accessible by a service provider.
The on-demand model was urbanized to repress the common challenge that an enterprise faces due to unexpected fluctuations in demands. Since, any enterprise's demand on computing resources can vary dramatically from one time to another, hence maintaining adequate resources to meet peak requirements can be expensive. On the contrary, if any enterprise tries to lessen the costs only by maintaining minimal computing resources, there will not be adequate resources to meet rise in requirements.
In simple terms, would say that
cloud server provides an on-demand access to the virtualized IT resources that can later be shared by others or subscribed by the
hosting service provider. It provides simple way to provide configurable resources by taking it from a unified pool. This unified pool comprises of networks, servers,
cloud storage, applications and services.